Technology Questions

Q:

What is immutable object? Can you write immutable object ?

Answer

Immutable classes are Java classes whose objects can not be modified once created. Any modification in Immutable object result in new object. For example is String is immutable in Java. Mostly Immutable are also final in Java, in order to prevent sub class from overriding methods in Java which can compromise Immutability. You can achieve same functionality by making member as non final but private and not modifying them except in constructor.

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Q:

Why do we need wrapper classes in Java?

Answer

Dealing with primitives as objects is easier at times. Most of the objects collection store objects and not primitive types. Many utility methods are provided by wrapper classes. To get these advantages we need to use wrapper classes. As they are objects, they can be stored in any of the collection and pass this collection as parameters to the methods.


 


Features of the Java wrapper Classes:


- Wrapper classes convert numeric strings into numeric values.


- The way to store primitive data in an object.


- The valueOf() method is available in all wrapper classes except Character


- All wrapper classes have typeValue() method. This method returns the value of the object as its primitive type.

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Subject: Java

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Q:

How can you find a PL/SQL block, if the cursor is open?

Answer

By use of %ISOPEN status variable.


 

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Subject: SQL

0 3165
Q:

What is the difference between OLE Server & OLE Container?

Answer

An OLE server application creates ole Objects that are embedded or linked in OLE Containers ex. OLE servers are ms_word & ms_excel. OLE containers provide a place to store, display and manipulate objects that are created by ole server applications. Ex. oracle forms is an example of an OLE Container.

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Q:

What are Spring beans ?

Answer

The Spring Beans are Java Objects that form the backbone of a Spring application. They are instantiated, assembled, and managed by the Spring IoC container. These beans are created with the configuration metadata that is supplied to the container.
Beans defined in spring framework are singleton beans. There is an attribute in bean tag named "singleton" if specified true then bean becomes singleton and if set to false then the bean becomes a prototype bean. By default it is set to true. So, all the beans in spring framework are by default singleton beans.

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Subject: Java
Job Role: Analyst , IT Trainer

4 3144
Q:

What is the BEST WAY to write test cases?

Answer

1) List down usecases (taken from business cases) from function specs. For each use case write a test case and categorize them into sanity tests, functionality, GUI, performance etc. Then for each test case, write its workflow. 


2) For a GUI application - make a list of all GUI controls. For each control start writing test cases for testing of the control UI, functionality (impact on the whole application), negative testing (for incorrect inputs), performance etc. 


 

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Subject: QA Testing

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Q:

What does a special set of tags do in PHP?

Answer The output is displayed directly to the browser.
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Subject: PHP

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Q:

What is an explicit constructor?

Answer

A conversion constructor declared with the explicit keyword. The compiler does not use an explicit constructor to implement an implied conversion of types. It’s purpose is reserved explicitly for construction

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Subject: C++
Job Role: Software Architect

0 3136